HIV remains a major public health problem, particularly for the Latina/o population. US-dwelling Latinas/os are at increased risk for HIV-infection compared to non-Hispanic whites, and suffer a disproportionate burden of HIV-associated neurocognitive disorder (HAND), which may be amplified with age. HIV-infected (HIV+) Latinas/os of Caribbean origin have the highest prevalence of HAND (~70%) of any racial/ethnic group in the US (HIV+ Mexican Americans: 44%; African Americans: ~40%, & non-Hispanic whites: ~40%). Older HIV+ Latinas/os (50 years) appear to be at even greater risk for HAND and cognitive decline than their non- Hispanic white counterparts. Moreover, the pattern of cognitive impairment in HAND appears to differ by ethnicity. In the general HIV population, HAND is characterized by impairments in processing speed, attention, and executive functioning consistent with involvement of the frontostriatal circuitry. In contrast, HIV+ Caribbean Latinas/os present a more amnestic profile with impaired learning and memory consistent with involvement of the medial temporal lobe circuitry. Despite these important disparities, differing cognitive profiles and possible differences in affected neural structures, the literature on HAND in Latinas/os is almost entirely cross-sectional, does not include HIV-uninfected (HIV-) controls, lacks any studies focused on brain integrity in this population, and has yet to examine the mechanisms underlying these disparities. Utilizing a biopsychosociocultural theoretical framework, the overarching goals of this study are to investigate whether older HIV+ Latinas/os of Caribbean origin demonstrate accelerated neurosenescence and different patterns of decline in cognitive function and brain integrity compared to other groups, and to uncover the biological (e.g., genetic predisposition [apolipoprotein-E ?4 allele], inflammatory biomarkers, cardiovascular burden) and sociocultural (e.g., social adversity, discrimination, stress) mechanisms conferring risk for neurodegenerative and cognitive changes in this population. To that end, this multidisciplinary study will deploy a longitudinal observational design with 110 HIV+ and 110 HIV-matched control adults (both groups will include: 70% Latina/o and 30% non-Hispanic white; 50% younger [21-45 yrs] and 50% older [60-80 yrs] over 36-months. All participants will complete laboratory, neuromedical, multimodal neuroimaging, and comprehensive cognitive and sociocultural assessments. Addressing dementia and HAND health disparities in Latinas/os is vital to: 1) improve our understanding of biological and sociocultural aspects of neurosenescence through the lens of HIV infection; 2) advance dementia research in other conditions (e.g., Alzheimer?s Disease [AD] & related dementias) by offering greater understanding of sociocultural variations in the neuropathogenesis of dementia; and 3) inform culturally-relevant and targeted interventions that could lead to better Latina/o cognitive and health outcomes in HIV and other chronic conditions that disproportionately burden this population. This work could also provide a framework for studying and addressing HAND in Latin American countries that also bear a heavy HIV burden.